0000001 - Document - Cover link:presentationLink link:calculationLink link:definitionLink 0000002 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS link:presentationLink link:calculationLink link:definitionLink 0000003 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) link:presentationLink link:calculationLink link:definitionLink 0000004 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF INCOME link:presentationLink link:calculationLink link:definitionLink 0000005 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME link:presentationLink link:calculationLink link:definitionLink 0000006 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS link:presentationLink link:calculationLink link:definitionLink 0000007 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF EQUITY link:presentationLink link:calculationLink link:definitionLink 0000008 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS - Southwest link:presentationLink link:calculationLink link:definitionLink 0000009 - 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Schedule of Goodwill (Details) link:presentationLink link:calculationLink link:definitionLink 9954482 - Disclosure - Background, Organization, and Summary of Significant Accounting Policies - Other Income (Deductions) (Details) link:presentationLink link:calculationLink link:definitionLink 9954483 - Disclosure - Background, Organization, and Summary of Significant Accounting Policies - Schedule of Redeemable Noncontrolling Interest (Details) link:presentationLink link:calculationLink link:definitionLink 9954484 - Disclosure - Background, Organization, and Summary of Significant Accounting Policies - Schedule of Earnings Per Share (Details) link:presentationLink link:calculationLink link:definitionLink 9954485 - Disclosure - Components of Net Periodic Benefit Cost (Details) link:presentationLink link:calculationLink link:definitionLink 9954486 - Disclosure - Revenue - Schedule of Regulated Operations Revenues: Natural Gas Distribution Segment (Details) link:presentationLink link:calculationLink link:definitionLink 9954487 - 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Disclosure - Segment Information - Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 9954499 - Disclosure - Segment Information - Accounts Receivable Not Eliminated During Consolidation (Details) link:presentationLink link:calculationLink link:definitionLink 9954500 - Disclosure - Segment Information - Schedule of Segment Reporting Information (Details) link:presentationLink link:calculationLink link:definitionLink 9954501 - Disclosure - Dispositions (Details) link:presentationLink link:calculationLink link:definitionLink 9954502 - Disclosure - Subsequent Events (Details) link:presentationLink link:calculationLink link:definitionLink